Method of providing axially aligned molded parts in non-aligned apertured walls of a preformed member

ABSTRACT

Method of manufacturing is presented which provides axially aligned finished molded parts, such as bushings and/or protuberances in non-aligned apertured wall portions of a preformed member, such as in the non-aligned opposing walls of a U-shaped chart-drive frame.

United States Patent Lux [54] METHOD OF PROVIDING AXIALLY.

ALIGNED MOLDED PARTS IN NON- ALIGNED APERTURED WALLS OF A PREFORMED MEMBER William J. Lux, Holland, Pa.

Assignee: Honeywell Inc., Minneapolis, Minn. Filed: Oct. 29, 1970 Appl. No.: 84,983

Inventor:

US. Cl. ..264/254, 264/251, 264/269,

264/318, 264/328 Int. Cl. ..B29f 1/00 Field of Search ..264/242, 254, 269, 328, 318, 264/251; 29/l49.5 NM

[ 51 Feb. 13,1973

[S6] Relerences Clted UNITED STATES PATENTS 3,540,314 ll/l970 Howard ..264l269 X 2,732,613 l/l956 Renholts ..29/l49.5 NM

Primary Examiner-Robert F. White Assistant Examiner-Willard E. Hoag Attorney-Arthur H. Swanson, Lockwood D. Burton and 1. Shaw Stevenson [57] ABSTRACT Method of manufacturing is presented which provides axially aligned finished molded parts, suchas bushings and/or protuberances in non-aligned apertured wall portions of a preformed member, such as in the nonaligned opposing walls of a U-shaped chart-drive frame.

6 Claims, 5 Drawing Figures PATENTEDFE'B13I973 3,716,613

' SHEET 10F 3 INVENTOR. WILLIAM J. LUX

AGENT.

PATENTEDFEB I 3 I973 SHEET 2 OF 3 INVENTOR. WILLIAM J. LUX BY 2 X A AGENT.

METHOD OF PROVIDING AXIALLY ALIGNED MOLDED PARTS IN NON-ALIGNED APERTURED WALLS OF A PREFORMED MEMBER In the manufacturing process of converting a plate member into a preformed member such as a U-shaped chart-driveframe, which is used to support rolls of chart paper and a chart drive shaft thereon, it is necessary to first punch holes in the opposite ends of the plate. The end portions of the plate are then bent in an upward direction to form the aforementioned U-shaped frame. Metallic bushings and/or protuberances such as stub shafts are then inserted in the apertured punched out wall portions in the upright portions of the U-shaped plate. The ends of sleeves on which supply and take-up rolls of the chart paper are wrapped are then mounted for rotation between the machined metallic bushings that are positioned on opposite sides of the upwardly extending portions of the U-shaped frame.

A chart drive shaft is also mounted for rotation at its ends on machined metallic stub shafts that are positioned on opposite sides of the upwardly extending portion of the chart frame.

One of the problems that has been encountered with chart-drive frames that have been constructed in the aforementioned manner is that binding occurs between the chart drive shaft and the metallic bushings on which the shaft is mounted Undesired binding also occurs between the ends of the spools and the associated stub shafts that are employed to support the ends of the supply and take-up portions of the chart paper on the upright portions of the frame.

It has been found that this binding is due to the paper being wrapped too loosely on one end of the aforementioned spools while it is being wrapped in too tight a fashion on the other end of these spools or a condition commonly referred to as telescoping.

This undesired telescoping of the chart paper occurs as a result of the non-uniform manner in which a press bends each of the end portions of the plate into an upright position. This bending operation throws the alignment of each apertured wall portion that is in one of the upright parts of the frame out of axial alignment with its separately associated apertured wall portion that is in the opposite upright portion of the frame.

In order to correct this misalignment and to prevent scrapping of these chart-drive frames it is necessary to perform an additional machine operation on the bushings and/or stub shafts that are in opposing wall portions of the chart frame. This machine operation is not desired since it consumes a great deal of additional manufacturing time and because of the high cost of the machinest and machine parts that are required to perform this additional operation.

It is therefore one of the objects of the present invention to set forth a remedy for this misalignment problem by providing a preformed member, such as a U-shaped chart frame, with axially aligned bushings and/or embossed portions that are molded in a preselected manner in non-aligned apertured wall portions that are formed in its upright parts.

It is also a further object of the present invention to provide a unique method of molding bushings and/or embossed portions in non-aligned apertured wall portion that are formed in the opposite walls of a U-shaped frame so that these molded parts will be in axial alignment with one another.

More specifically it is another object of the present invention to accomplish the aforementioned manufacturing feat by retaining each opposite wall of the U- .shaped frame in a preselected position in a mold so that material to form pairs of bushings and/or embossed portions can be injected into the non-aligned apertured wall portions and into other portions of the mold surrounding each of these preformed apertured wall portions so that these bushings and/or embossed portions will be formed in axial alignment with one another.

A better understanding of the present invention may be had from the following detailed description when read in connection with the accompanying drawings in which:

FIG. 1 shows the initial condition of a flat plate with the previously mentioned apertured wall portions therein to show the condition this plate is in before it is bent into its final preformed condition, such as a chart frame;

FIG. 2 shows how an edge of the base of the frame is aligned with horizontally positioned pins and vertically displaced stop buttons in a mold and further shows how the right and left ends of the plate shown in FIG. 1 are pressed downwardly from this position into a vertical position to form a U-shaped chart frame that has the previously mentioned misaligned apertured walls formed therein;

FIG. 3 shows the way in which the different opposite upright portions of the U-shaped frame shown in FIG. 2 are mounted in preselected related positions in a mold in order that the bearing surfaces of the bushings, embossed portion, or other protuberances that are molded therein can be formed in axial alignment with one another;

FIG. 4 shows a typical section of a mold that surrounds an apertured wall portion in either one of the upright portions of the U-shaped member and how av core pin and other parts of this mold are positioned to allow molten bearing or non bearing material to flow about it and the wall forming the aperture and within the confines of the parts of the mold to form each of the aforementioned aligned finished molded bushings and/or embossed portions, through section 4:4 of FIG.

FIG. 5 is a typical sectional view to show that the apertured wall portions in the upright portions of the U-shaped frame are all axially displaced from those' formed in its left upright portion and further shows how the molded finished bearing surfaces formed by the inner surfaces of the bushings and the outer surfaces of the protuberances or embossed portions are mounted in opposite apertured wall portions of the vertical parts of the U-shaped member so they are in axial alignment with one another.

FIG. 1 shows, by way of illustration, a punched out preformed plate 10 that is to be used in its final preformed condition as a chart frame. This plate 10 has a base portion 12 having two parallel edges l4, 16. The

left and right end portions 18, 20 of the plate 10 are provided with associated pairs of punched out apertured wall portions 22, 24; 26, 28; 30, 32; 34, 36. The centers of each pair of apertured wall portions e.g., 26, 28, are laid out on the flat plate 10 so that they are at the same selected distance from their associated plate folding line 38 or 40.

FIG. 2 shows a view looking at the other side of FIG.

1 with the ends 18, 20 of the plate bent in a vertical direction.

It should be noted that bending of the ends 18 and 20 of plate 10 into the position shown in FIG. 2 causes distortion of the plate and the apertured wall portions 22, 26, 30, 34 on one end 18 of the frame 10 to be shifted out of alignment with each of the related apertured wall portions 24, 28, 32, 36 on the other end 20 of the frame 10.

FIG. 2 and the left end of FIG. 3 show a reference edge portion 16 of the base part 42 of the frame 10 in physical contact with aligned pins 44, 46, 48 which protrude from a mold 511.

FIG. 3 shows a pusher plate 51 engaged with and applying a force to the edge 14 of the base portion 42 in the direction of the arrow 52 to retain the edge 16 in tight non-movable relationship against the pins 44 48.

FIG. 2 also shows the base part 42 of the frame 10 in contact with a suitable number of cylindrical shape stops for example 53, 54, 55, 56, 57 which protrude at equal distances away from a fiat external side surface 58 of the mold S0.

A suitable clamp 60 such as a toggle clamp is shown retaining the frame 10 in the aforementioned. position in FIG. 3 so that any desired thermosetting or thermoplastic molding material 62 can be injected into each mold as shown in FIG. 4.

When the part to be molded in this manner is to be used as a self lubricating bushing or an embossed portion on which a shaft is to be slidably mounted or rotated, a self lubricating material e.g., glass filled nylon is preferably employed for this material 62.

Each of the apertured wall portions 22 36 are aligned in a fixed position in the mold 50 as previously described, and in a manner shown by way of example for apertured wall portion 34 in FIG. 3. In this way each wall portion will be connected by way of an injection nozzle 64 in the molded plate 66 so that plastic material 62 can flow under pressure from a molten plastic source, not shown, in the direction of the arrow 67.

FIG. 4 shows that the mold 50 is comprised of three plates namely a central plate 66 and two additional plates 68, 70 that are located on either side of the plate 66. The plate 70 is shown having a core pin 72 extending therefrom that protrudes through the apertured wall 36.

FIG. 2 and the upper portion of FIG. 3 shows the reference edge portion 16 of the base part 42 of the frame 10 in physical contact with pin 74 and two additional pins, not shown, which are positioned in alignment with pins 74. This alignment is done in a manner similar to the way the edge 16 of the base part 42 was aligned with the previously described pins 44, 46, 48 when the frame was placed in its previously described first position at the left side of mold 50 as shown in FIG. 3.

The pusher plate 76 is shown in FIG. 3 as being engaged with and applying a force to the edge 14 of the base portion 42 in the direction of the arrow 78 to retain the edge 16 in tightv non movable engagement against the pin 74 and the other two previously mentioned pins that are aligned with pin 74.

' FIG. 3 also shows the base part 42 of the frame 10 in contact with a suitable number of cylindrically shaped stops 53 57' that are similar to the stops 53 57 previously described and which protrude at equal distances away from a flat external top surface 80 of the mold 50.

One end of a suitable clamp 82 such as a toggle clamp, is shown retaining the frame 10 in the aforementioned position so that previously mentioned plastic material 62 can be injected into each apertured wall portion in a manner similar to that shown in FIG. 4 previously described.

It can be seen that the same reference edge 16 of the frame 10 is aligned with reference surfaces formed by the previously mentioned pins, forexample, pins 44, 46, 48 of the mold 50 when the upright portions 18, 20 of the frame 10 is placed in each of the positions shown in FIG. 3.

It therefore follows that each of the opposite pairs of molded parts 84, 86; 88, 90; 92, 94; 96, 98; will be provided with axially and/or concentrically opposite aligned bearing surfaces 100, 102; 104, 106; 108, 110; l 12, 1 14.

It can also be seen because of the way the frame is aligned in the mold the outer surfaces of any embossed portions, such as the embossed portions 116, 1 18 of the molded parts 92, 94, can be molded so that they are concentric with one another and spaced at different distances from a common axis 120.

Furthermore, other embossed portions such as the embossed portions 122, 124 of the molded parts 84, 86 can be molded so that their outer circumferential surfaces are in alignment with one another and located at the same radial distance from the axis 126.

FIG. 5 shows the finished molded bearing surfaces 1 12 and 114 of the bushings 96, 98 shown mounted in the frame 10 having axially aligned surfaces therein that are useful in supporting the ends of a sprocket type chart drive shaft thereon which shaft in turn has a conventional sprocket wheel thereon for engaging holes in a strip chart, not shown.

The aligned pair of finished molded bearing surfaces 108, 110 and embossed portions 116, 118 of the molded parts 92, 94 are beneficially employed to support the ends of e.g., a supply roll of chart paper thereon. Since this pair of supporting molded parts 94, 96, are aligned with one another the sprocket holes on the aforementioned chart are always kept in alignment with the sprocket wheel on the aforementioned drive shaft that is supported between molded parts 96, 98.

The aligned parts of finished molded bearing surfaces 104, 106 formed in the molded parts 88, 90 are usefully employed to' support a chart takeup spool thereon in parallel alignment with the chart drive and supply spools.

The aligned pair of finished molded bushings 84, 86 are employed to support a shaft thereon that will allow the aforementioned chart to be either directed from the supply spool for wrapping about the previously mentioned takeup spool or to allow a strip of the chart to be directed downwardly away from the platen 10 and the previously mentioned chart supply spool.

Although not shown in detail in FIG. 3 it should be understood that the tie rods 128, 130, 132, 134, which pass through the parts 66, 68, 70 of the mold 50 are employed to retain these parts as shown in FIG. 4 in fixed relation with one another during the injection of the molten plastic material 62.

From the aforementioned description it can be seen that an apparatus and a method of manufacturing the apparatus has been described that provides axially aligned molten bushings and/or embossed portions in misaligned apertured wall portions of a preformed member, such as a chart frame 10, so that the previously mentioned problem of binding cannot occur when a support member, such as a drive, takeup and/or a chart supply shaft supported thereon is placed between opposite pairs of these molded parts lclaim:

1. A method of forming an axially aligned pair of molded cylindrical bearings having cylindrical bearing surfaces in nonaligned apertured wall portions that are formed in opposite walls of a U-shaped preformed member so that each of said resulting pair of cylindrical bearing surfaces can be spaced at an equal radial distance about a common axis, comprising the steps of positioning a straight reference edge and a reference flat surface portion of the preformed member that extends between its opposite walls respectively against associated pin supporting surfaces and flat stop members of a mold, retaining the straight reference edge of said preformed member in a fixed position against said pin supporting surfaces and said flat surface against said flat stop members in said mold and injecting molded material into each of said nonaligned apertured wall portions to form each of said molded cylindrical bearings while the preformed member is in said last mentioned position. v

2. The method of forming molded cylindrical bearings in each one of said nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein the molding material is injected into said'nonaligned apertured wall portions in said opposite walls to form bushings therein that have bearing surfaces that are in axial aligned relationship with one another.

3. The method of forming molded cylindrical bearings in each one of said nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein the molding material is injected into said nonaligned apertured wall portions in said opposite walls that are of a polygonal shaped configuration to form bearing surfaces that are concentrically aligned with one another.

4. The method of forming molded cylindrical bearings in each one of said nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein the molding material is injected into said nonaligned apertured walls to form embossed portions thereon whose outer surfaces are concentrically in alignment with one another.

5. The method of forming molded cylindrical bearings therein in each one of said two nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein the molding material is injected into said nonaligned apertured walls to form protuberances protruding therefrom whose outer surfaces are in alignment with one another.

6. The method of forming molded cylindrical bearings in each one of said two nonaligned apertured wall portions in the opposite walls of a preformed U- sha ed member as defined in claim 1 and wherein the mo ding material is in ected into said nonaligned apertured walls to form embossed portions protruding therefrom whose outer surfaces are in alignment with one another and which are spaced at the same radial distance from their common axis. 

1. A method of forming an axially aligned pair of molded cylindrical bearings having cylindrical bearing surfaces in nonaligned apertured wall portions that are formed in opposite walls of a U-shaped preformed member so that each of said resulting pair of cylindrical bearing surfaces can be spaced at an equal radial distance about a common axis, comprising the steps of positioning a straight reference edge and a reference flat surface portion of the preformed member that extends between its opposite walls respectively against associated pin supporting surfaces and flat stop members of a mold, retaining the straight reference edge of said preformed member in a fixed position against said pin supporting surfaces and said flat surface against said flat stop members in said mold and injecting molded material into each of said nonaligned apertured wall portions to form each of said molded cylindrical bearings while the preformed member is in said last mentioned position.
 2. The method of forming molded cylindrical bearings in each one of said nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein the molding material is injected into said nonaligned apertured wall portions in said opposite walls to form bushings therein that have bearing surfaces that are in axial aligned relationship with one another.
 3. The method of forming molded cylindrical bearings in each one of said nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein thE molding material is injected into said nonaligned apertured wall portions in said opposite walls that are of a polygonal shaped configuration to form bearing surfaces that are concentrically aligned with one another.
 4. The method of forming molded cylindrical bearings in each one of said nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein the molding material is injected into said nonaligned apertured walls to form embossed portions thereon whose outer surfaces are concentrically in alignment with one another.
 5. The method of forming molded cylindrical bearings therein in each one of said two nonaligned apertured wall portions in the opposite walls of a preformed U-shaped member as defined in claim 1, wherein the molding material is injected into said nonaligned apertured walls to form protuberances protruding therefrom whose outer surfaces are in alignment with one another. 